Japanese carmaker Nissan hopes the launch of its new mass-market electric car is a "game-changing" event that will transform the auto sector and help triple its profits, say industry analysts.

But they warned that its success is riding on whether the price is really low enough to win over the masses or not.

Nissan announced in London on Monday that its new Leaf vehicle will be sold in western Europe for under 30,000 euros (37,105 dollars), after government incentives that are aimed at encouraging green car use.

The car, which has a top speed of more than 140 kilometres (90 miles) per hour and is powered by a lithium battery, will go on sale in Portugal and the Netherlands in December, and in Britain and Ireland in February 2011.

The Leaf -- which stands for Leading, Environmentally Friendly, Affordable, Family car -- is billed by Nissan as the world's first mass-produced electric vehicle with zero emissions.

"We do believe this car is a game-changer in terms of this technology and it will play a role in the future," Simon Thomas, Nissan's senior vice president, sales and marketing, told AFP at a London press conference on Monday.

The firm, which is 43.4-percent owned by France's Renault, also forecast that electric vehicles will account for 10 percent of world car sales by 2020.

Japan's number three automaker had revealed last week that it bounced back into profits in its 2009/2010 financial year -- and forecast profits to more than triple on hopes for its new electric car and emerging market demand.

European reservations for the Leaf can be made from July, while the car will be rolled out in every major western European country by the end of next year.

Nissan added that its electric car will cost around the same as a diesel or hybrid vehicle.

"The Renault-Nissan alliance is investing over four billion euros to lead the auto industry in electric vehicles, with eight products across three brands," Thomas said.

The huge investment includes five battery plants and seven confirmed assembly factories, including one in Sunderland, northeastern England.

Industry experts were impressed by the advent of Nissan's mass-market electric car -- but added that the vehicle was not cheap.

"It's the beginning of a very different sort of industry," Peter Wells, automotive expert at Cardiff University, told AFP.

"It does mark a quantum leap forward in terms of mass-market product cars," he said, adding that the Leaf is "not by any means a cheap car".

Nissan's five-seater hatchback has a range of 160 kilometres (100 miles), can be recharged through domestic power supply in about eight hours, or topped up to 80 percent capacity in 30 minutes at electric recharging stations.

John O'Connor, director of Warwick University's low carbon vehicle transportation project, described the Leaf as "ground-breaking".

"It is ground-breaking for the first high-volume electric vehicle," O'Connor told AFP, but also cautioned that it was "quite expensive ... and really for the early adopters".

Nissan hopes electric vehicles will boost growth and compete with Mitsubishi Motors' i-MiEV and Fuji Heavy, which makes the Subaru Plug-in Stella.

Toyota, the world's largest car maker, has focused on petrol-electric hybrids such as the Prius, but has also promised to launch its own electric car by 2012.

Nissan does not want to be beaten by Toyota in the marketplace for electric emission-free cars, according to Wells.

"It shows that Renault-Nissan are well ahead of the pace on this," Wells added.

"Toyota took a 10-year lead on the industry with hybrid technology. This is an attempt to grab back the initiative."

However, he sounded a note of caution about the economic outlook amid the eurozone's mounting crisis over high levels of state debt.

"It's becoming unstable -- it could turn quite nasty and if it does then the car industry could be in a difficult situation," said Wells.

From December, Nissan will sell the Leaf in Japan for 2.99 million yen, when government incentives are included.

Technological breakthroughs in the development of long-lasting lithium-ion batteries have significantly and lowered the cost of electric vehicles and increased their range and top speed potential.

The Leaf will not be the first mainstream electric car on the market. Mitsubishi Motors recently rolled out its "i-MiEV" minicar while Fuji Heavy Industries launched the Subaru plug-in STELLA.